1. Field of the Invention
The present invention relates to a light guide structure including a light guide plate and a light source, and being adapted for a backlight module.
2. The Prior Arts
Backlight modules are now widely used in many kinds of electronic products. For example, displays of notebook computers, mobile phones, and liquid crystal televisions do not emit light by themselves, and require backlight modules for providing light sources.
A typical backlight module includes a light guide plate and a light source. Light emitting diodes (LED) are often employed serving as light sources of backlight modules for those electronic products demanding a relatively thin thickness. With respect to such a backlight module, the LED light source is positioned at a lateral side of the light guide plate. The light guide plate has a first surface and a second surface opposite to the first surface. A reflective sheet is provided at the first surface, and a plurality of optical sheets including a diffusing sheet and a prism sheet are provided at the second surface. An outer frame is provided for framing all of the components. In operation, the LED light source emits a light, and the light is inputted into light guide plate from the lateral side of the light guide plate. A part of the light is reflected by the reflective sheet, and sequentially passes through the diffusing sheet and the prism sheet, and is then outputted therefrom.
When serving for a backlight module having a relatively small area, the light sources are usually provided at one lateral side of the light guide plate. However, when serving for a backlight module having a relatively large area, if the light sources are only provided at one side of the light guide plate, the light inputted into the light guide plate gradually attenuates while being transmitted to the other side of the light guide plate. This often causes a nonuniform illuminating condition of the light guide plate. As such, a large size light guide plate is often provided with light sources at both sides for solving the problem of the single side light sources.
FIG. 1 is a schematic diagram illustrating a conventional backlight module including a light guide plate and light sources assembled together. Referring to FIG. 1, no matter the light sources are provided to one side, two sides, or even more sides of the light guide plate 1, the conventional backlight module is generally configured by providing LEDs 2 onto a circuit board 3, and then assembling the LEDs 2 and the circuit board together to the lateral side(s) of the light guide plate 1. Accordingly, in fabricating such a backlight module, the LEDs 2 must be previously welded to the circuit board 3. Then, the circuit board 3, together with the LEDs 2 welded thereon, is secured to the light guide plate 3. As such, the process of the fabrication is relatively complex, and needs a high fabrication cost.